package com.gujia.concurrency.example.commonUnsafe;

import com.gujia.concurrency.annoations.NoThreadSafe;
import com.gujia.concurrency.annoations.ThreadSafe;
import lombok.extern.slf4j.Slf4j;

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Semaphore;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * StringBuilder 是线程不安全的
 */
@Slf4j
@NoThreadSafe
public class StringExample1 {
    
    //请求总数
    public  static  int clientTotal = 5000;
    
    //同时并发执行的线程数
    public static int threadTotal = 200;
    
    public static StringBuilder stringBuilder= new StringBuilder();

    public static void main(String[] args) throws Exception {

        ExecutorService executorService = Executors.newCachedThreadPool();
        
        final Semaphore semaphore = new Semaphore(threadTotal);
        final CountDownLatch countDownLatch = new CountDownLatch(clientTotal);
        
        for (int i = 0 ; i<clientTotal;i++){

            executorService.execute(()->{
                try{
                    semaphore.acquire();
                    add();
                    semaphore.release();

                }catch (Exception e){
                    //log.error("exception",e);
                    e.printStackTrace();
                }

                countDownLatch.countDown();
            });

        }

        countDownLatch.await();
        executorService.shutdown();
        System.out.println("StringBuilder length:"+stringBuilder.length());

    }

    private static void add() {

       // count.incrementAndGet();
       stringBuilder.append("1");
    }
}
